docs: def _get_destcache(self, graph, orig, branch, turn, tick, *, forward):
          """Return a set of destination nodes succeeding ``orig``"""
          destcache, destcache_lru, get_keycachelike, successors, adds_dels_sucpred = self._get_destcache_stuff
          lru_append(destcache, destcache_lru, ((graph, orig, branch), turn, tick), KEYCACHE_MAXSIZE)
          return get_keycachelike(
              destcache, successors, adds_dels_sucpred, (graph, orig),
              branch, turn, tick, forward=forward
          )